BAA Exhibition meeting

[Rick]

The British Astronomical Association's exhibition meeting in Cambridge today was interesting more for the various stands than the talks this year. Two things caught my eye.

The first was an interesting design of telescope. Initially I thought it was a simple Newtonian, but when I looked closer it turned out to be catadioptic. The primary mirror is apparently spherical, and the aberration is corrected using two doublet lenses, one in front of the secondary, and another in the base of the focuser. The secondary was mounted on a full-aperture optically flat front plate. Only prototypes were on display. The aim of the design seemed to be to get a flat field from a scope with a short tube with an eyepiece in the usual Newtonian position and a relatively small central obstruction. However, it looks like it'll end up being fairly expensive.

The second was the stand belonging to the BAA's radio astronomy group, which has been dormant for years, but which seems now to have something starting. Part of their aim is to produce some simple-to-use radio-astronomy kit. It's not yet clear how much it might all cost, nor what might be achieved, but if suitably synchronised timing can be arranged (and that is a big "if") then long-baseline interferometry might be possible. Even without that, there are some solar monitoring tasks that can be performed with modest equipment.

There were some impressive images of Jupiter from Damien Peach. He took his 9.5" SCT to Barbados, where, it seems, the seeing was excellent. Apparently he came back from Barbados with several hundred gigabytes of images. The detail he's captured rivals the best that professional astronomers could manage ten years ago. Included in today's presentation was an animation of Europa emerging from a transit. Even Europa had some detail on its surface in these images! And just to prove it wasn't a fluke, he'd also taken some images of Mars. Now, when Mars was last at opposition images with this much detail weren't too hard to find, but at the moment Mars is only 6 seconds of arc across, not something nearer 30. Keep an eye out for images of his in the amateur astronomy press and websites. They're worth seeing.

The other main talk concerned photometry of asteroids, a task that can be done using webcams these days, and one where amateurs can collect data that could be of use to professionals.

All in all an interesting day.